Pure JS button click

PureJS_ButtonClick

<div id="option">
    <button class="valueButton"
            value="0">0
    </button>
    <button class="valueButton"
            value="1">1
    </button>
    <button class="valueButton"
            value="2">2
    </button>
    <button class="valueButton"
            value="3">3
    </button>
</div>
<script>
    // not strictly an array Array-Like
    var buttonArray = document.getElementsByClassName("valueButton");
    var getButtonValue = function () {
        var attribute = this.getAttribute("value");
        alert(attribute);
    };
    for (var i = 0; i < buttonArray.length; i++) {
        buttonArray[i].addEventListener('click', getButtonValue, false);
    }
</script>